Yeah I think I remember seeing that when I played through. I think it was also mentioned briefly elsewhere on the forum. I don't think they plan on fixing it. If you want to skip the trainers that's up to you, but you're missing out on exp.

Yeah, that's the only one that I could do it on, and it only works on that side of the pillar, but as I said, it lets you skip almost the entirety of the gym, which I recognize isn't necessarily an unfair advantage (except for speedruns). However, a bug's a bug, and this one lets players skip content that isn't intended to be skipped.

That being said, it is a gym that specializes in illusions, so...accidentally on purpose?